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authorThomas Zimmermann <tzimmermann@suse.de>2022-04-29 12:08:32 +0200
committerThomas Zimmermann <tzimmermann@suse.de>2022-05-03 16:04:22 +0200
commit3ed3811283ddbc959db564efce6f0988c63bc03c (patch)
treeaeaf3a9e958c5fc8642d6bd138dd70f7163d5dda /drivers/video
parent56c134f7f1b58be08bdb0ca8372474a4a5165f31 (diff)
fbdev: Refactor implementation of page_mkwrite
Refactor the page-write handler for deferred I/O. Drivers use the function to let fbdev track written pages of mmap'ed framebuffer memory. v3: * keep locking within track-pages function for readability (Sam) v2: * don't export the helper until we have an external caller Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220429100834.18898-4-tzimmermann@suse.de
Diffstat (limited to 'drivers/video')
-rw-r--r--drivers/video/fbdev/core/fb_defio.c53
1 files changed, 38 insertions, 15 deletions
diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c
index 1bdef5c241f7..3f9bb4725119 100644
--- a/drivers/video/fbdev/core/fb_defio.c
+++ b/drivers/video/fbdev/core/fb_defio.c
@@ -143,26 +143,17 @@ int fb_deferred_io_fsync(struct file *file, loff_t start, loff_t end, int datasy
}
EXPORT_SYMBOL_GPL(fb_deferred_io_fsync);
-/* vm_ops->page_mkwrite handler */
-static vm_fault_t fb_deferred_io_mkwrite(struct vm_fault *vmf)
+/*
+ * Adds a page to the dirty list. Call this from struct
+ * vm_operations_struct.page_mkwrite.
+ */
+static vm_fault_t fb_deferred_io_track_page(struct fb_info *info, unsigned long offset,
+ struct page *page)
{
- struct page *page = vmf->page;
- struct fb_info *info = vmf->vma->vm_private_data;
struct fb_deferred_io *fbdefio = info->fbdefio;
struct fb_deferred_io_pageref *pageref;
- unsigned long offset;
vm_fault_t ret;
- offset = (vmf->address - vmf->vma->vm_start);
-
- /* this is a callback we get when userspace first tries to
- write to the page. we schedule a workqueue. that workqueue
- will eventually mkclean the touched pages and execute the
- deferred framebuffer IO. then if userspace touches a page
- again, we repeat the same scheme */
-
- file_update_time(vmf->vma->vm_file);
-
/* protect against the workqueue changing the page list */
mutex_lock(&fbdefio->lock);
@@ -197,6 +188,38 @@ err_mutex_unlock:
return ret;
}
+/*
+ * fb_deferred_io_page_mkwrite - Mark a page as written for deferred I/O
+ * @fb_info: The fbdev info structure
+ * @vmf: The VM fault
+ *
+ * This is a callback we get when userspace first tries to
+ * write to the page. We schedule a workqueue. That workqueue
+ * will eventually mkclean the touched pages and execute the
+ * deferred framebuffer IO. Then if userspace touches a page
+ * again, we repeat the same scheme.
+ *
+ * Returns:
+ * VM_FAULT_LOCKED on success, or a VM_FAULT error otherwise.
+ */
+static vm_fault_t fb_deferred_io_page_mkwrite(struct fb_info *info, struct vm_fault *vmf)
+{
+ unsigned long offset = vmf->address - vmf->vma->vm_start;
+ struct page *page = vmf->page;
+
+ file_update_time(vmf->vma->vm_file);
+
+ return fb_deferred_io_track_page(info, offset, page);
+}
+
+/* vm_ops->page_mkwrite handler */
+static vm_fault_t fb_deferred_io_mkwrite(struct vm_fault *vmf)
+{
+ struct fb_info *info = vmf->vma->vm_private_data;
+
+ return fb_deferred_io_page_mkwrite(info, vmf);
+}
+
static const struct vm_operations_struct fb_deferred_io_vm_ops = {
.fault = fb_deferred_io_fault,
.page_mkwrite = fb_deferred_io_mkwrite,